Pump-cylinder head



.l. jW. DREW.

PUMP CYLINDER HEAD- APPLICATION m n Nov. 25. 1,921.

1 428,2722. Patented Sept. 5, 1922.

jizuerzior @Zkw ZMDneaz maize FTTZNT JOHN W. DREW, OF ST. LOUIS, MISSOURI, ASSIGNOR TO MOON BROTHERS MANU- FAGTURING GOMTANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF IVIISSOURI.

PUMP-CYLINDER HEAD.

Application filed November 25. 1921. Serial No. 517,660. 1 M.

ing is a full, clear, and exact description,

such as will' enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this application, in whichv Figure 1 is a top plan view of a double cylinder pump containing my improved pump cylinder head.

Figure 2 is a similar view with the cap plate removed.

Figure 3 is a vertical sectional view.

Figure 4 is a similar view of the small cylinder showing the parts in different position.

Figure 5 is a plan view of the flexible gasket.

Figure 6 is a side elevational view of said gasket.

This invention relates to a new and useful improvement in pump cylinder heads and is designed particularly for use in connection with double cylinder pumps commonly employed in inflating pneumatic tires.

The object of my invention is to provide a tight joint for the piston rod where it passes through the head at the upper end of the small compression cylinder.

In the drawings, 1 indicates the pump base, 2 the large or primary compression cylinder, and 3 the smaller and final compression cylinder. l and 5 indicate the piston rods. 6 is the cap piece preferably made of pressed metal which is arranged over the upper ends of both cylinders and which directly engages the upper end of the larger cylinder 2. This cap piece serves as a guide for the piston rods. The upper end of cylinder 3 has mounted thereon either by threading or by pressing a casting 7 which casting forms an extension of cylinder '3 and provides a differential bore by virtue of the shoulder afforded by the upper end of said cylinder 3.

8 indicates a flexible gasket preferably made of leather or other suitable material which is interposed between the casting 7 9 indicates a floating dish-shaped washer, preferably made of metal, whose marginal flanges normally rest loosely upon the upper end of the cylinder 3. As shown in Figure 4, the lower end of piston rod 5 is provided with a leather cup-shaped Washer 10, held 111 position by suitable well known means such as metallic washers 11 and nut 12.

Then the rod 5 is drawn upwardly and the leather piston cupapproaches the upper limit .of its movement, the floating washer 9 will be picked up and carried with the piston until its upper end engages the flat under-surface of the flexible washer 8 which tends to absorb the shock of theublow. In

this manner, the edges of the leather piston cupshaped washer are protected by being held fron contact with the flexible gasket and by virtue of the recess in the upper face of the dish-shaped floating washer, the inclined flanges of the flexible gasket are likewise protected. Thus, in addition to providing'a cushion stop for the pistonrod 5, this floating dish-shaped washer serves as a protecting medium for the inclined flanges of the flexible gasket, as well as the cup-shaped washer of the piston.

The air compressed by the piston head in the upper end of cylinder 3 is forced through an opening in said upper end and out through a tube 13. The cap piece 6 is held in position by screws 14 which enter openings in the casting 7.

Washer 9 also serves as a spacer for axially aligning piston rod .5 in cylinder 3. This function is especially advantageous when the pump is being assembled as the accurate positionin of rod 5 by washer 9 eliminates the necessity of shifting cap piece 6 t0 and fro until the holes for screws 14 are aligned.

Such shifting, as has been required hitherto,

frequently causes gasket 8 to be caught and displaced or torn or otherwise disarranged, which result would not be noticeable until the pump was operated and when it would be necessary to remove cap piece 8 to correct this defect.

Vi hat I claim is:

1. A closure for pump cylinders comprising the combination of a cylinder and its piston, a flexible gasket arranged on said cylinder and having flaring walls for coopcrating with the piston rod, a cap piece for holding said flexible gasket in position, and a floating washer arranged between the end or the cylinder and said flexible gasket, said washer being provided with a recess designed to accommodate the flaring flanges of the flexible member.

2. A pump cylinder closure comprising a cylinder having a diflerential bore at its end, a flexible washer adapted to embrace the piston rod, and a floating washer operating in the differential bore of the cylinder and. against said flexible washer.

3. A closure for pump cylinders comprising the combination of a cylinder. and its cylinder head, a piston and piston rod adapted to operate therein, a floating washer supported within the cylinder and having a zone of movement adjacent the cylinder head, said washer being operable by the piston ring to arrest the stroke of the piston and protect injuriable parts thereof.

4. A closure for pump cylinders comprising the combination of a'cylinder having a differential bore in its end, a dish-shaped floating washer arranged in said bore, a piston rod and a piston head on said rod, he latter having a cup-shaped washer the flanges of which are designed to embrace the floating washer when the same is moved to act as a stop to arrest the piston rod.

5. The combination of a pump cylinder, a flexible gasket having inclined flanges embracing the piston rod and arranged at the end of the cylinder, a floating dish-shaped washer designed to engage said gasket and receive said inclined flanges in the recessed ace thereof, a piston rod and a piston head on said rod, the latter having a cup-shaped flexible washer which surrounds the projecting side of the dish-shaped floating washer when the same is lifted by the piston to act as a stop to arrest the piston.

In testimony whereof I hereunto afiix my signature this 22nd day of November, 1921.

JOHN W. DREW. 

